i have a 25 yr old rws 34 177 cal with separate scope rings, at 15yds it is shooing 1/2" low with scope adj maxed, so it looks like a need a 1 pc scope base with a taper. how do i know what to order, ii would like to get the poi around 2 inches high at 15yds so i can shoot out to 5oyds. right now the scope adj is maxed all the way out. if i am correct the front of the scope has to go down, is this correctchet